What characteristics of earth make it habitable by humans ?

Question

What characteristics of earth make it habitable by humans ?

Answer 1

No more dinosaures

Answer 2

Oxygen, fresh water, land masses, climate, diversity of lifeforms, atmosphere and atmospheric pressure, plants life, carbon based life.

Answer 3

The four major characteristics are water, the Sun, minerals, and oxygen. All three work together. The Sun allows for life by providing warmth and allowing the growth of plants (refer to photosynthesis). Water also is needed for plants to grow, and minerals are needed as well because they make up rocks, and rocks make up soil as well, so soil is pure minerals created by erosion and weathering. Water and sunlight follow the rules of yin and yang, which mean "the dark side of the hill and the bright side of the hill", respectively. Without water, the sunlight would dry out life, while at the same time, the Sun's energy is needed to balance out water. I am actually not being spiritual, but I am trying to show you in a more basic way how the characteristics of earth work together. You see, it's not about earth being habitable by humans necessarily, but it's about earth being habitable by any living thing. Next, oxygen is needed for most mammals (in your question humans) the breathe and therefore survive, while, as you will see, plants need carbon dioxide in the air to survive. There are many elements I'm sure that are needed for plants and animals for survive.

Answer 4

Humans have evolved to suit earth's unique aspects. As we are now so well adapted most other planets aren't suitable. However if earth had been like a different plant to start likely we would have evolved differently to suit the different earth.

The minimal requirements for life that a species equivalent to humans in intelligence could evolve out of are somewhat undecided. It is likely however that at least you would require water and a temperature suitable for water to exist.

In future planets colonizable by the human race may not even have that requirement due to our growing ability to shield ourselves from the forces of nature and to reuse resources.

Answer 5

Warm temperature, plenty of water.